It's never the right time to ask a woman when she's going to give her child a sibling. Photograph: Keith Morris / Alamy

When you're a woman of a certain reproductive age, there's a predictable timeline of nagging that emerges over the years. First come the seemingly well intentioned questions about when you'll settle down and get married. If you do get hitched, you'll start fielding questions about when you'll have a child before the cake is even served. Then, once you do become a mother – and thus complete all the milestones of appropriate womanhood that American culture dictates – the next question inevitably is: "When will you do it again?"

Not only are these questions rude, but they rely on stereotypes about what makes a woman – and a family – "complete". The assumption that you need more than one child to be a "real family" is so pervasive that even I didn't initially escape.

I grew up with a sister whom I love dearly, and my husband has siblings. We had always, without question, planned on having more than one child – but sometimes life doesn't work out the way you'd like it to.

It's not that I think most people are actively trying to be rude or invasive, but the question and its honest answers are by their very nature intimate. Still, I've found if I don't immediately get into my personal medical history, the unsolicited comments that follow make things worse. People say things like, "But she'll be lonely without a brother or sister!", or "You don't want her to be spoiled, do you?", or the appalling "Don't be selfish".

Once I tell people about my particular circumstances, they tend to pipe down – but not always. I've actually been told that I shouldn't worry about dying and leaving my daughter behind because "God will take you when he wants, whether you're pregnant or not" – and that doctors inflate the risks associated with pregnancies after illnesses like mine.

What many people don't realize is that, for months after Layla's birth, I scoured the internet for information on women who had second pregnancies after diseases like mine, hoping against hope that the doctors were wrong. The results were terrifying – but still I sought out multiple doctors and specialists to give me the answer I desperately wanted to hear. I didn't only want to have a larger family, or focus on giving Layla a sibling: I wanted to have a "normal" pregnancy-and-birth experience. It took me a long time, and a lot of pain, to accept that it was never going to happen.

What made that realization even harder to come to, though, were the stereotypes about only children: they're over-indulged; they don't know how to share; they're lonely and maladjusted. My life and (and therapists' bills) would have been much improved if anyone told me about all the benefits of having just one child, of which there are many.

For women in particular – since they still end up doing the majority of domestic work and child care – one child is a lot less of that "second shift" work than multiple children.

It also turns out that having just one child (especially now that Layla is a toddler) is quite ... humane. My husband and I go to restaurants and actually get to eat. We sleep well. We both get to work at jobs that we love while dedicating all our free time to Layla. We can travel to see my in-laws more often than we would otherwise, and we can save money for a house that we otherwise would have spent on child care. Parenting only one child allows me both to be a good mother and find ways to enjoy my own life as an individual – and give Layla more of a little bit of everything.

All of these are not universal perks, I know: I have a partner who takes an equal part in parenting, a steady salary and a supportive family. Not everyone who has or wants children – whether it's one or five – is so fortunate. (If we wanted people to be happy with their family lives no matter what the number of children they have, we could start by mandating paid parental leave and subsidized child care.)

But for me, for now, these are the upsides that keep me going. While I've come to love our only-child life, I haven't completely given up on the idea that there are more children in my family's future. There's more than one way to have a baby and we'll definitely consider those options – but not just to give Layla a playmate, keep her from being spoiled or because of the social expectation that it takes more than just one child to have the perfect family.

If we do bring another child into our little family, we will do so out of the pure desire to meet and raise another incredible child – and if that never happens, so be it. I am very happy, and complete, with our one and only. I think that the person who benefits most from having a happy mom is Layla.

Twelve years younger than her only brother, Kelly Rose Bradford grew up feeling like an only child – lonely and used to her own company. Now 40 and a single mother, she feels guilty that her son has no siblings to share his life with